Mesosphere
Dana Desonie, Ph.D.
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Printed: September 13, 2014
AUTHOR
Dana Desonie, Ph.D.
www.ck12.org
C HAPTER
Chapter 1. Mesosphere
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Mesosphere
• Describe the mesosphere.
What can make your blood boil?
Believe it or not, if you were in the mesosphere without a space suit, your blood would boil! This is because the
pressure is so low that liquids would boil at normal body temperature.
Mesosphere
Above the stratosphere is the mesosphere. Temperatures in the mesosphere decrease with altitude. Because there
are few gas molecules in the mesosphere to absorb the Sun’s radiation, the heat source is the stratosphere below. The
mesosphere is extremely cold, especially at its top, about -90o C (-130o F).
Air Density
The air in the mesosphere has extremely low density: 99.9% of the mass of the atmosphere is below the mesosphere.
As a result, air pressure is very low ( Figure 1.1). A person traveling through the mesosphere would experience
severe burns from ultraviolet light since the ozone layer, which provides UV protection, is in the stratosphere below.
There would be almost no oxygen for breathing. And, of course, your blood would boil at normal body temperature.
Summary
• The mesosphere has a very low density of gas molecules.
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FIGURE 1.1
Although the mesosphere has extremely
low pressure, it occasionally has clouds.
The clouds in the photo are mesospheric
clouds called noctilucent clouds.
• Temperature decreases in the mesosphere with altitude because the heat source is the stratosphere.
• The mesosphere is no place for human life!
Explore More
Use this resource to answer the questions that follow.
https://www.youtube.com/watch?v=R5JFXb0lkLk
1. Where is the mesosphere?
2. What is the temperature gradient of the mesosphere?
3. What happens to a rock falling through space in the mesosphere? Why don’t this happen in the thermosphere?
Review
1. Why would a person get severe burns in the mesosphere?
2. Why would a person’s blood boil in the mesosphere?
3. How can meteors burn in the mesosphere when the air density is so low?
References
1. Jan Erik Paulsen. Noctilucent clouds in the mesosphere.
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